Re: Here we go again - more trouble

Thanks Andy, I am gradually learning the hard way...

Keith Clark

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Andy Wander <awander@v...>
wrote:

> And I will chime in, too.
>
> Disconnect the motor from a known good drive, take the fuse out on

that

> drive, and see if you still get voltage across THAT fuse holder.
>
> Most people don't realize that in a circuit, if you "open" the

circuit, and

> current stops flowing, you will measure the entire power supply

voltage

> across the "opening". This is easily seen by applying Kirchoff's

law, when

> you will see that with no current flowing(open circuit) there will

be no

> voltage drop across any of the things that usually drop voltage(by

I*R), so

> the entire Supply voltage must be "dropped" across the open circuit.
>
> This is why switching the Neutral instead of the Hot in AC power

wiring is

> not a good idea, with the switch in the Neutral line, there will bo

one

> White wire on the switch that is at 120VAC(or whatever your color

code/line

> voltage is). Most people look at a white wire as "safe to touch",

but in

> this instance it would not be safe.
>
> Andy Wander
> Verrex Corporation
>
>
> -----Original Message-----
> From: washcomp [mailto:jeff@w...]
> Sent: Wednesday, October 20, 2004 9:47 AM
> To: CAD_CAM_EDM_DRO@yahoogroups.com
> Subject: [CAD_CAM_EDM_DRO] Re: Here we go again - more trouble
>
>
>
> Keith:
>
> I picked up this part of the thread rather late so I appologize if
> someone has suggested this before:
>
> The problem with troubleshooting a complete system is that a

problem

> with one part often affects other components making the finding of
> the bug difficult.
>
> Try to break the system in half (thirds?). The problem is either
> with the motor or the drive or the wiring harness. We'll assume

for

> now that your drive is good (it's new after all) - oh hell, lets

test

> it anyway. Tie the drive to a known working motor and see if all

is

> as expected. OK, now we know it's OK. Test the windings of the
> motor for expected resistance as compared to your good motor
> (assuming they are identicle). If the resistance you get is too
> small to accurately measure, tie the coils in series and measure
> across all of them. If this doesn't work (reading still too

small),

> take a battery and put the windings across it in series and measure
> the voltage across each winding. They should be the same (ohm's

law

> and all that). If this all checks out then the motor should be OK.
>
> If the motor is OK and the drive is OK, that leaves your wiring.

I'm

> not sure how you made up the harness, but likely there's some issue
> (broken wire, shorted wire, mis-labled wire etc.).
>
> Might want to check wiring to the fuse holder from the power supply
> and the fuse/fuse holder while you're at it as long as everything

is

> disassembled anyway. It's consivable that the issue is there :-)
>
> Hope this helps,
> Jeff
>
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "Keith Clark" <mail@t...>
> wrote:
> >
> > I thought that the voltage reading across the open fuse holder
> > suggested a problem and did not know that that was normal. At

any

> > rate, I disconnected the motor and still found the same voltage
> > reading across the open fuse holder. So at that point I reasoned
> > that there must be something wrong with the connector from the
> Gecko
> > and replaced it. Then the reading across the fuse holder went to
> > zero! However, this was done without the capacitor installed
> across
> > terminals 1 and 2. Does it seem possible that the connector

could

> be
> > bad? I did not see any stray strands of wire and could not

measure

> > any shorts between the terminals of the connector. Possibly the
> > capacitor in place makes a difference? I did replace the

capacitor.

> >
> > Thanks
> > Keith Clark
>
>
>
>
>
> Addresses:
> FAQ: http://www.ktmarketing.com/faq.html
> FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/
> Post Messages: CAD_CAM_EDM_DRO@yahoogroups.com
>
> Subscribe: CAD_CAM_EDM_DRO-subscribe@yahoogroups.com
> Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@yahoogroups.com
> List owner: CAD_CAM_EDM_DRO-owner@yahoogroups.com, wanliker@a...,
> timg@k...
> Moderator: pentam@c... indigo_red@q... davemucha@j...
> [Moderators]
> URL to this group: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO
>
> OFF Topic POSTS: General Machining
> If you wish to post on unlimited OT subjects goto:
> aol://5863:126/rec.crafts.metalworking or go thru Google.com to

reach it if

> you have trouble.
> http://www.metalworking.com/news_servers.html
>
> http://groups.yahoo.com/group/jobshophomeshop I consider this to

be a

> sister site to the CCED group, as many of the same members are

there, for OT

> subjects, that are not allowed on the CCED list.
>
> NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING

THEM.

> DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........
> bill
> List Mom
> List Owner
>
>
> Yahoo! Groups Links